This invention relates to valuable devices such as, for example, computer disc (CDs) and digital video discs (DVDs) and in particular to methods and apparatus for patterning or encoding these devices to impede their being copied without authorization.
For ease of discussion the invention will be illustrated using CDs and DVDs. However, it should be understood that in the specification to follow and in the appended claims, when reference is made to CDs and/or DVDs other devices and instruments are included, although not specifically identified as such.
CDs and DVDs are subject to being counterfeited (“pirated”) by individuals or entities who copy true, authorized or valid CDs and DVDs.
As noted in the above identified applications Ser. Nos. 09/745,512 and 09/190,760, the inventive concepts described for impeding the counterfeiting of cards, instruments and documents are also applicable to systems for impeding the counterfeiting (“pirating”) of optical data storage discs. Optical data storage discs may include compact discs (CDs) and digital video discs (DVDs). A difference between CDs and DVDs is that the CD may have information stored on only one exterior surface while a DVD may have information stored on both exterior surfaces. Thus, in the case of a CD, information is optically read from only one side, while in the case of a DVD information is read from both sides, but normally only one side at a time.
Also, as noted above, there is a significant problem related to the counterfeiting (“pirating” and “copying”) of DVDs and CDs. Major software companies (e.g., Microsoft, Sony) are losing a significant amount of revenue due to the falsification of their intellectual property in the form of counterfeit CDs and DVDs. This problem is especially rampant in Asian countries where the amount of counterfeit products can be in excess of 90%.
Many different schemes have been tried to impede the counterfeiting of CDs and DVDs using digital encryption techniques. Some of these schemes are very clever, but they are prone to being undone by any “hacker” setting his/her mind to breaking the encrypted code.